A magnetic storage system such as a tape drive using magnetic tapes generally involves the problem of head contamination. Because the read and write magnetic head comes in contact with magnetic tapes the read and write magnetic head may accumulate debris. Such debris on the read and write magnetic head may cause data transfer errors. Therefore, it is desirable to subject the read and write magnetic head to periodic cleaning treatments.
Prior art devices have used methods in which the read and write magnetic head is cleaned using a separate cleaning cassette. However, these methods require the use of a device which is separate from the tape drive and must be inserted by the user. Apparent drawbacks to this method are potential loss of the cleaning cassette and inconsistent and untimely use of the cleaning cassette by the operator. Accordingly, there have been recent tape drive devices which have integrated the cleaning apparatus within the tape drive.
With reference to FIGS. 1, 2 and 3 there are illustrated a prior art automatic read and write magnetic head cleaning apparatus for a magnetic tape drive system.
FIG. 1 illustrates a known magnetic tape drive system constructed in a manner as will be described hereinafter. Read and write magnetic head 10 is mounted on base plate 12 of the magnetic tape drive system. Magnetic head 10 is mounted on the base plate 12 via a carriage 14. Carriage 14 is vertically and slidably mounted on a frame 16 by side rails (not shown).
In the above-described magnetic tape drive system the known head cleaning apparatus is constructed as will be described hereinafter. A guide post 18 is fixedly mounted at an end thereof to the base plate 12. Further, a slider 20 is slidably mounted on the guide post 18 and mechanically coupled to a drive cam 22 via a pin 52 integral to the slider 20 and a channel 48 in the drive cam 22. Drive cam 22 is rotatably mounted to the base plate 12. A brush 24 is fixed to the slider 20 by a brush holder 26. Brush 24 is in an interference condition between head 10 and slider 20.
With reference to FIGS. 1, 2 and 3 the operation of the above-known head cleaning device for a magnetic tape drive will now be described. When a magnetic storage cassette (not shown) is loaded from the tape drive system a drive train (not shown) causes the drive cam 22 to rotate clockwise. The rotation of the drive cam 22 urges the slider 20 to move downwardly causing the brush 24 to wipe across the magnetic head 10. During the unloading of a magnetic storage cassette, the drive train causes the drive cam 22 to rotate in the counterclockwise direction thus urging the slider 20 to move upwardly wiping the brush 24 across the magnetic head 10. The guidepost 18 locates the slider 20 adjacent to the drive cam 22 and the magnetic head 10. The anti-rotation portion 30 integrally connected to the slider 20 prevents the slider from rotating and decoupling from the drive cam 22.
However, the above-known magnetic head cleaning device has disadvantages as will be described hereinafter. The proximity of the brush with respect to magnetic head is critical to ensure proper cleaning. If the slider upon which the brush 24 is mounted is too close to the magnetic head 10, due to a prescribed manufacturing tolerance band for positioning of the guidepost, the drive cam, the slider and the magnetic head 10, the brush 24 will exert excessive forces against the magnetic head 10 and will cause premature wearing of the brush 24 and subsequent ineffective cleaning of the magnetic head 10. On the other hand, if the manufacturing tolerances in positioning of the various parts allow the brush 24 to be positioned too far from the magnetic head 10 ineffective cleaning of the magnetic head 10 will occur. Therefore, the known head cleaning device is not effective in cleaning the magnetic head 10. An improved magnetic head cleaning apparatus is needed to accommodate the variation in positioning of a cleaning apparatus with respect to a magnetic head due to manufacturing tolerances.